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I don't want to start an argument, but . . . . > >

What are the gear lube recommendations for a non-limited slip differential. I've played with the Search engine but as you well know, it sux. It appears that it needs to be a 75W-90 GL-5 lube which meets the BMW SAF-XO specification - whatever that is.

I was planning to go with an appropriate Redline or Royal Purple fluid but again, the compatibility specs are less obvious than ATF or engine oil specs.

I'm sure there are several good choices but at 80,000 miles on the original "Lifetime" gear oil, I think it's time for a change.

I know this had been answered dozens of times but I can seem to find a single one of them.

Thanks guys. Great recommendations all. > > >

I decided to go with the Redline High Performance Gear Oil. They are all fine products but I can get the Redline delivered for a few $$ less than either the Lubromoly or the RP products and I'm certainly comfortable with the Redline family of products.

Note to Jim: the RP Synchromax is their manual transmission lubricant. The RP Max-Gear is their GL-5 gear oil.

Life would be a lot more complicated without the support you guys provide on Roadfly.

OOPS, meant to say Max Gear not SynchroMax

"Drive It Like You Stole It, A Sickness for Quickness"The Bottle Rocket "King of Spray" 2 Stage Nitrous OxideDare to be different and stand out among the crowd of me-to-cars!No guts, no glory!Tire smoke, not traction control!Zionsville all aluminum radiator to replace the 3 leak prone Nissens Radiators!

Switched to RL Bcuz it had better shear properties

"Drive It Like You Stole It, A Sickness for Quickness"The Bottle Rocket "King of Spray" 2 Stage Nitrous OxideDare to be different and stand out among the crowd of me-to-cars!No guts, no glory!Tire smoke, not traction control!Zionsville all aluminum radiator to replace the 3 leak prone Nissens Radiators!

Both are 14mm. I got a 3 pack of 1/2" drive (m)

new alu crush washers, or ditch 'em &the old plugs

and go with the new differential plugs BMW made. I did a mini FYI writeup on them, and I think they are fantastic as the new seal is built into the plug and they seal great against the differential. Cost me like $4 for each new plug, iirc. (not to say that the old plugs are bad, but alu crush washers on diffs are a thing of the past, for the very reason they degrade over time---check these pics of the old alu washers on the diff when taken off:

Here's pics, old plug on the left, new plug on the right:

The new plugs have a lot going for them, i.e., pay close attention the interior of the plug, how they are beveled and machined, so that in the future, you don't have to fight (if your plugs are a bit corroded) to get the 14mm hex in there. Plus, the depth of them and the way they are threaded up to the rim versus the older plugs. They just seal all around better, and you feel it putting them in versus putting one of the old ones back in.

Eurodavid

P.S. Filehorse, I know this is not what you may want to hear & may cause others to go apoplectic, but any, I repeat ANY differential fluid that is new will suffice. The key, like the tranny, is that it is "new". Buy the cheapest 75w-90 gear lube oil, and you will be fine. I find it much better to buy 2-3 bottles of the least expensive stuff (i.e. Quaker State makes some great, inexpensive 75w-90 gear lube oil that is just as good as any gear lube 2-3 times its price), and change the diff fluid every 15-20k. Plus, if you do two flushes of diff fluid within 15k, you differential will love you that much more (and be that much cleaner) than if you just did it once and wait another 25-35k to do it again.

The new plug looks very similar to the fill & > >

drain plugs on my ZF 5HP19. I do like the new design. I'll probably "invest" in a couple of those for the diff. Thanks for the heads-up.

I don't disagree about the choice of differential gear oil and certainly if you are going to change it very often. I'm going with the Redline and I'll probably put the diff on the same 40,000 mile schedule as the transmission.

If you're investing in drain plugs, get the best

The BavAuto drain plugs have the new O-ring and a magnet.

BavAuto, where Bavarians shop
Vin
98 540 Sport with everything & extra hots
BMW CCA, Boston Chapter
"The 540 is the head-case supermodel girlfriend..." Eric S.
"The worst thing you could do with your money is save it." ~ Jackie Gleason
If everything seems under control, you're just not going fast enough. Mario Andretti
The United States is a nation of laws: poorly written and randomly enforced. - Frank Zappa

Vin, I can't get your link to work..what am I

doing wrong? They sound great, especially if a super-strong magnet is built right into them. I use the world's strongest known magnets in my tranny pan---you can get two of them if you have any old hard drives laying around--each IDE or SATA hard drive has two of them in it, and they fit perfectly in the tranny pan (fastening them in there was a bit of a trick, though). Each of those hard drive magnets (about size of your pinky sliced in half horizontally) will lift something like 18-20 pds to over 50 ft in the air---they're really impressive. Only thing is gotta be careful messing with these things; for example, if you get any finger skin between metal and those magnets, they will literally pinch the skin right off as they glob on to the metal like instant superglue.